I wonder why the frame is made out of bolted beams with holes in them, are bolts and holed beams easy to find or something?
I mean I can imagine that if you have the tools to build those, you'd have a welder as well. Granted, welding might be a bit more challenging than cutting beams and drilling holes.
Perforated steel tube is a readily available material and a ratchet is a cheaper and much lower skill tool than a welder. Also seems like customization is one of the project goals.
I would imagine that if wanted to weld it instead the design would also work for you.
Where do you get 1/4 wall perforated tube? It sounds expensive compared to regular box tube straight from the mill. And each bolted connection made with graded fasteners is going to cost several dollars, which adds up very quickly.
A circular saw, a mag drill, and a stick welder could take you a long way on a project like this, and you could use regular steel plate, tube, angle bars, etc. I think a lot of cost and weight is being sacrificed in the name of "modularity", for questionable benefit.
For steel as thick as this, stick welding is very forgiving though. Big heatsinks, hard to melt through. Most people can probably learn to make (ugly but) strong enough welds in an afternoon.
They will look strong enough. Whether they really are strong enough or not is a completely different story and I guarantee that you won't learn that in an afternoon. Veteran of many thousands of welds here, welding is a real skill and with gear like this making a mistake could cause injury or death to operator or bystanders. Better make sure you know how to weld beforehand.
From what I remember from back when I first read up on this project: The goal is for as much of the construction to be done with simple tools and materials that can be stored long-term.
If you need to, hypothetically, bury your society-bootstrapping supplies, your wrenches and hole bar will probably survive. But a welder may not.
Fair enough, without electricity you might still be able to drill holes in things, it just takes a good while.
Mind you, I've seen some... interesting welders cobbled together, I saw one that was a load of wire wrapped around a rubber inner tyre. Here [1] is one made from a microwave transformer.
It's really, really, really difficult for me to imagine a "society-bootstrapping" event where conveniently dimensioned steel, diesel/gasoline engines and fasteners are readily available but thousands of old, easily repairable tractors are not.
General construction kit for real world applications. In theory you could take a machine apart and use the beams for some other machine. A smaller kit could build any of the machine designs as needed.
The problem with grid-beam is that it really only seems to make sense if you A) have lots of grid-beams in various sizes already, and B) are making, taking apart, and repurposing things frequently. Without A, making grid beams is a lot more work than just purpose-cutting your pieces, and without B, you don't really have a reason to drill all those extra holes.
I've built a ton of stuff with grid beam. I never drilled my own holes. For big stuff, like making office furniture [1], I buy "pre-drilled" aluminum beams from McMaster-Carr [2]. I would buy lots of long lengths, then cut down to the required size as needed. And years ago, I also "miniaturized" grid beam down to Lego-compatible, 3D printable components that I use for prototyping [3].
The grid beam book talks a lot about what you need to make beams from scratch. You don't have to do that. You can buy (or print!) beams and get to work right away.
I lived with Phil and RJ Jergenson for a couple years around 2012, tried to learn from their experience and mistakes. They weren't happy with 1ft lengths in every project, even though they were an improvement in reusability over all lengths free-for-all. I've since moved all the replimat designs to use lengths 2, 3, 4, 5, 10, 15, 20, 25, and 30 only. Which allows for center pivots and divisible-by-two lengths whereas the Jergensons could only divide by two. We also hit countertop height a little better. Little tweaks.
I try to communicate with everyone listed in the "Friends" section on the right hand side of https://www.replimat.org/ regularly. I'm excited that things seem to be gathering steam for all of us.
I mean I can imagine that if you have the tools to build those, you'd have a welder as well. Granted, welding might be a bit more challenging than cutting beams and drilling holes.